Nacre, also known as mother of pearl, is an organic-inorganic composite material produced by some molluscs as an inner shell layer. It is strong, resilient, and iridescent.
00000Chief sources of mother of pearl are the pearl oyster, found in warm and tropical seas, primarily in Asia; freshwater pearl mussels, which live in many rivers of the United States, Europe, and Asia.
00000Nacre appears iridescent because the thickness of the aragonite platelets from which it is constructed, is comparable to the wavelength of visible light. This results in constructive and destructive interference of different wavelengths of light, resulting in different colours of light being reflected at different viewing angles.

Location - USA, Japan, Asia.